The investment is in fact an extension of the $7.6 million Series A round raised from Benchmark Capital and Omidyar Network in August 2011.

Christoph Janz, founder and managing partner of Point Nine Capital, tells me that it made sense for CouchSurfing to get a European investor on board considering its global scope, and that they were excited to participate in the funding even if they were a little “late to the party”.

I had a chat with CouchSurfing co-founder Casey Fenton earlier today at the DLD Conference in Munich, and he told me that the site now has 3.5 million registered members in over 81,000 cities around the world.

Founded in 2004, CouchSurfing transformed from a decidedly non-profit organization to a so-called B Corporation (i.e. a for-profit company that is dedicated to creating public benefit) in 2011 after raising funding from Benchmark Capital and Omidyar Network.

Fenton said that CouchSurfing differs from service providers like Airbnb, Wimdu and 9flats in the sense that they enable the sharing of experiences as a global community of like-minded people, and not by creating a marketplace that’s centered around transactions.

Evidently, the San Francisco-based company plans to make money at some point, but how remains unclear: Fenton said they’re going to experiment with a number of revenue models in the future to try and find one that doesn’t interfere with the user experience whatsoever.

CouchSurfing is currently focused more on enhancing the usability of the site to make the end-to-end experience for users, particularly new ones, a lot smoother than it is today.

Finally, Fenton acknowledged that there was some uproar in the community when they raised venture funding, mainly from a small core group of users who consider the ‘CouchSurfing ideal’ to be an integral part of their identity, but that members have not left in droves.